1. Field of the Invention
The present invention relates to disk brake devices known as floating-type disk brake devices. In particular, the present invention relates to floating-type disk brake devices in which a guide portion, disposed on at least one end of a disk pad in a rotational direction of a disk pad, is supported by a support portion provided on a mount such that the guide portion is movable in an axial direction of the disk but is prevented from being removed from the support portion along the radial direction of the disk pad.
2. Description of the Related Art
Floating-type disk brakes having various constructions are known. For example, Japanese Laid-Open Patent Publication No. 2000-27905 (U.S. Pat. No. 3,303,780) teaches a disk brake in which guide portions extending from both sides along the rotational direction of a disk pad are axially movably supported by support portions formed as recesses in a mount. Liners are disposed between the pad and the mount and have resiliently deformable arms that urge the pad to be tilted in the rotational direction of the disk (i.e., tilted counterclockwise around an axis parallel to the axis of rotation of the disk, as shown in FIG. 5). Thus, the resilient arms apply a torque to the pad, pressing the pad against the mount. The effect is that the pad is prevented from possible rattling movement relative to the mount. In addition, when the pad slidably contacts the disk, the pad receives more torque in the rotational direction of the brake disk, and this torque applies an additional moment force to the pad. In other words, the pad receives the moment produced by the disk and the moment produced by the resiliently deformable arms. As a result, the pad is strongly pressed against the mount by a force large enough to effectively prevent any rattling.
However, because the pad is tightly pressed against the mount by the biasing force of the resilient arms and by the moment produced by the brake disk, a very large friction force is generated between the pad and the mount when the pad is moved in the axial direction of the brake disk. In such a case, the pad cannot move smoothly in the axial direction.